Google has a history of your searches.
After much criticism they have allowed
for you to opt out of it by clicking on a link.
When you do google search then the icon in upper right corner
looking like a CogWheel click on it and look for the drop down
list where it mention you can stop the result based on your personal
history of earlier searches.
Suppose I love Trikes of the HPV sort. Human Powered Vehicles (HPV)
not to be mistaken with Petrol or Gas Diesel powered such Bikes.
Then google knows which such Trikes that I looked at last time
I made a search.
So if I opt out then they will treat the weighted result differently
now when I tell them to ignore previous personal history of such searches.
Aint that cool or what to say

Why there is no link? Google is regional in that living in Sweden the
link goes to the Swedish version. So depending on where you live
each such link would differ. Take a look
Swedish text is "Inaktivera anpassade resultat baserade på sökaktivitet."
Google translate this to.
Turn off personalized results based on search activity.
That is a rather good translatio. Better than my poor grasp of English
